The invention relates to a continuous monitoring system of the electrical conduction of a mains system comprising first and second conductors fed by an A.C. voltage source.
In an electrical mains system, the problems of bad conduction are linked either to faulty connections, for example the connections of the bars of a low voltage switchboard, or to faulty contacts of switchgear inserted in the mains system, for example circuit breaker contacts. Loosening of a connection leads to local overheating which may be responsible for damage to nearby equipment and may cause fires.
It has been proposed to monitor certain contacts by means enabling local overheating to be detected. According to a first monitoring procedure, the contact temperature is measured, a thermistor or a thermocouple being associated with each contact to be monitored. Such a procedure requires a large number of temperature sensors, one per contact to be monitored, each of the sensors in addition having to be connected to an information processing device, which implies a large number of wires. According to a second procedure, a camera is used to take thermographic photos to detect the hot spots on a busbar. There is naturally no way of placing a camera opposite each point to be monitored and such a procedure cannot be used for continuous monitoring, but only for the purposes of occasional maintenance.